Single brain metastasis: whole-brain irradiation plus either radiosurgery or neurosurgical resection.

BACKGROUND: The current study was conducted to compare neurosurgical resection (NR) followed by whole-brain irradiation (WBI) (NR + WBI) with WBI followed by radiosurgery (WBI + RS) in patients with a single brain metastasis. METHODS: The outcome of 41 patients treated with WBI + RS was retrospectively compared with 111 patients who received NR ;+ WBI with respect to local control of the treated metastasis and survival. Eleven additional potential prognostic factors were investigated, including WBI schedule, patient age, patient gender, Karnofsky performance score (KPS), primary tumor type, extracerebral metastases, recursive partitioning analysis (RPA) class, interval between the first diagnosis of cancer to the treatment of brain metastasis, metastatic site, maximum diameter of the metastasis, and graded prognostic assessment (GPA) score. RESULTS: The 1-year local control rates were 87% after WBI + RS and 56% after NR + WBI (P = .001). Using the Cox proportional hazards model, the treatment regimen remained significant (risk ratio [RR], 2.46; 95% confidence interval [95% CI], 1.29-5.17 [P = .005]). On the multivariate analysis, local control was also found to be associated with the maximum diameter of the metastasis. The 1-year survival rates were 61% after WBI + RS and 53% after NR + WBI (P = .16). Acute and late toxicities were similar in both groups. On the multivariate analysis, KPS, extracerebral metastases, RPA class, and the GPA score were found to be independent predictors of survival. CONCLUSIONS: The use of WBI + RS resulted in significantly better local control of the treated metastasis than NR + WBI. Survival was not found to be significantly different in either group. Because WBI + RS is less invasive than NR + WBI, it appears to be preferable for many patients with a single brain metastasis. These results should be confirmed in a randomized trial.

Older age and greater carotid intima-media thickness predict ischemic events associated with carotid-artery stenting.

BACKGROUND: Carotid-artery stenting (CAS) may be complicated by stroke. We aimed to determine predictors of procedure-related ischemic events. METHODS: We analyzed new ischemic lesions in diffusion-weighted MRI (DWI) after CAS in 147 patients with symptomatic high-grade carotid stenosis. Nine covariates were assessed as potential risk factors for new lesions in DWI: age, gender, hypertension, diabetes, dyslipidemia, smoking status, severity of stenosis, side of intervention and carotid intima-media thickness (IMT). RESULTS: From the nine covariates assessed, only age and IMT were independently associated with new DWI lesions. An age of 68 years and an IMT of 1.5 mm gave the best separation between high- and low-risk populations. The subgroup of patients <68 years who had an IMT ≤1.5 mm had the lowest rate of new DWI lesions (11.3%). This rate was greater in patients ≥68 years (30.0%; odds ratio, OR, 3.4; 95% confidence interval, CI, 1.1-10.8) and in patients with an IMT >1.5 mm (36.4%; OR 4.5; 95% CI 1.2-17.0) and was particularly high in patients aged ≥68 years with IMT >1.5 mm (69.6%; OR 18.0; 95% CI 4.8-71.9). CONCLUSIONS: Older age and greater IMT are independently associated with the risk of CAS-related ischemic events. This risk is particularly high in those patients in whom older age and greater IMT coincide.

Acute and prophylactic endovascular treatment of internal carotid artery stenosis.

Stroke is the third most common cause of death in the USA. Up to 20% of all strokes are caused by internal carotid artery (ICA) stenosis. This article reviews the treatment of ICA stenosis, its indication, and its relevance for stroke prevention. The article also discusses the indication of ICA stenosis treatment in an acute stroke situation and offers pathophysiological commentary.

Cerebral embolism during carotid artery stenting: role of carotid plaque echolucency.

BACKGROUND: Carotid artery stenting (CAS) is associated with the risk of intraprocedural stroke. A better understanding of specific risk factors could help to improve the procedure and to reduce the overall risk of CAS. We addressed the role of carotid plaque echolucency as potential risk factor for cerebral embolism during CAS. METHODS: We prospectively evaluated carotid plaque echolucency by use of a computer-assisted measure of echogenicity, the gray scale median (GSM), in 31 consecutive patients with symptomatic high-grade carotid stenosis that were scheduled to undergo CAS. Dual-frequency transcranial Doppler ultrasound was used to detect solid cerebral microemboli during CAS. RESULTS: 27 of the 31 patients met all inclusion/exclusion criteria.Solid cerebral microemboli were detected during 17 of 27 CAS procedures. The GSM of the target plaques was lower in subjects with intraprocedural embolism (37.9 +/- 20.8) than in those without (58.2 +/- 25.7) (p = 0.040). A receiver-operating characteristic analysis showed that the GSM that gave the greatest separation between plaques with a higher and a lower probability of intraprocedural embolism was 50: the proportion of subjects with intraprocedural embolism was 85% in CAS of echolucent plaques (GSM <50) and 42% in CAS of echogenic plaques (GSM > or =50) (p = 0.031). CONCLUSIONS: CAS of both echolucent and echogenic carotid plaques may be associated with cerebral embolism, particularly CAS of echolucent plaques. Plaque echolucency alone does not reliably identify patients at particularly high risk of intraprocedural embolism, but should be considered as one of a broad panel of risk factors of CAS.

Comparative study of portal vein embolization versus portal vein ligation for induction of hypertrophy of the future liver remnant using a mini-pig model.

SUMMARY BACKGROUND DATA: The extent of hepatectomies is limited by the functional reserve of the remnant liver. The introduction of preoperative portal vein occlusion techniques to induce a preoperative hyperplasia of the future liver remnant has reduced the risk of postoperative liver failure. However, it has remained a matter of debate whether partial portal vein embolization (PVE) or suture ligation of the portal branches during exploration is the preferred technique. We compared both techniques under standardized experimental conditions in a large animal model by means of effectiveness and pathophysiologic differences. METHODS: Thirteen mini-pigs underwent portal vein ligation (PVL), 11 mini-pigs underwent PVE of 75% of the liver volume, and 6 underwent a sham operation. The animals were killed after 28 days. Laboratory liver function and damage parameters, lobar liver-to-body weight indices, portal and arterial flow alterations, and histologic changes were assessed. Ex situ arteriograms and portograms were performed to examine adaptive changes in the macroarchitecture of both vascular systems. RESULTS: The liver-to-body weight index of the nonoccluded lobe was highest after PVE (0.85) versus 0.6 (P < 0.05) after PVL. There was no significant reduction in global serum parameters reflecting total liver function. After 4 weeks, the PVL group consistently exhibited hepatopetal portal flow in the ligated lobes, which was present but significantly decreased after PVE. The ex situ angiography after PVE and PVL revealed the development of portal neocollaterals in the portal-occluded liver parts. CONCLUSIONS: Both PVL and PVE are able to induce hypertrophy of the future liver remnant. In comparison, PVE is the more effective technique to increase the future liver remnant. This is due to a more effective, durable occlusion of the portal branches. Formation of collaterals between occluded and nonoccluded liver parts seems to be the cause of inferior regeneration in the ligation group.

MRI abnormalities in normal-appearing brain tissue of treated adult PKU patients.

PURPOSE: To detect possible subclinical pathological brain changes a study on adult phenylketonuria (PKU) patients by using quantitative MRI methods was performed, since neuropsychological and cognitive deficits in treated patients with PKU have not yet been shown to correlate clearly with the brain lesions identified by conventional MRI. MATERIALS AND METHODS: Eight subjects, four PKU patients with well-documented dietary treatment and four age- and sex-matched adult controls, underwent MRI, including a triple echo sequence and a diffusion tensor imaging sequence. Brain maps of T2 relaxation time (T2), relative proton density (PD), and fractional anisotropy (FA) as well as apparent diffusion coefficient (ADC) were derived for each subject. T2, PD, FA, and ADC were measured in 22 predefined regions of gray matter (GM) and white matter (WM) on the corresponding maps, and compared with those of four age-matched healthy adult controls. RESULTS: In addition to a prolonged T2 value measured in affected WM, as expected, we observed a significant shortening of the T2 relaxation time and reduction of ADC in normal-appearing brain tissue and an increased proton density in both GM and WM of the patients. No differences were observed in FA values between controls and patients. CONCLUSION: Repeatedly reduced T2 relaxation time, ADC, and increased proton density without changes in FA indicate a higher cell-packing density in normal-appearing brain without changes in the directedness of fibers. These structural changes may be related to neuropsychological and cognitive deficits in treated PKU patients.

Clinical applications of quantitative T2 determination: a complementary MRI tool for routine diagnosis of suspected myelination disorders.

BACKGROUND AND AIMS: Though magnetic resonance imaging (MRI) plays an important role in studying pathological changes in central nervous system, a quantitative measure of contrast variance on MRI, allowing the detection of subtle signal variances in pathological processes, is not readily available for routine imaging. We report on the first experiences with evaluation of routine T2 relaxation time measurement as a diagnostic tool in routine imaging of suspected myelination disorders. METHODS: Twenty patients suffering from defined or suspected myelination disorders were examined by MRI. T2 relaxation time maps of the brain were derived from a triple spin echo sequence. T2 values were measured for each patient by regions of interest (ROI) analysis. As references age-dependent T2 prediction values in normal maturating brains were calculated by using a biexponentional function reported earlier. Deviations from these prediction values were used as an assisting tool both for detection of pathology and for monitoring of changes over time. These quantitative results were compared to conventional visual inspections by two independent neuroradiologists. RESULTS: In 18 patients with single diagnostic MRI, the T2 measurements were more graduated or definite in 9/18 cases, confirmatory in 9/18 cases. In two patients with MRI follow up, the dynamic clinical course of the disease had no correlate in visual inspection of the images but was associated with the quantitative T2 values. CONCLUSIONS: Quantitative T2 measurement is a promising tool for routine imaging as a complementary method in detecting and monitoring of suspected myelination disorders.

MR evaluation of dural ectasia in Marfan syndrome: reassessment of the established criteria in children, adolescents, and young adults.

PURPOSE: To retrospectively evaluate known criteria for assessment of dural ectasia by using magnetic resonance (MR) imaging in children, adolescents, and young adults with and those without Marfan syndrome. MATERIALS AND METHODS: Local ethics committee approval and informed consent were obtained. MR images of the lumbar spine in 28 patients with clinically proved Marfan syndrome (group A; 17 male, 11 female; age range, 4-21 years; mean, 12.1 years), seven patients with suspicion of Marfan syndrome (group B; six male, one female; age range, 6-18 years; mean, 10.4 years), and 55 patients without Marfan syndrome (group C; 26 male, 29 female; age range, 4-20 years; mean, 10.7 years) were evaluated retrospectively for dural ectasia criteria (scalloping, dural sac ratio, nerve root sleeve diameter, sagittal dural sac width at S1 greater than that at L4) and according to classifications by Ahn et al and Fattori et al. For statistical comparison of results, one-way analysis of variance with Scheffe post hoc comparisons was used, with an overall two-tailed significance at alpha = .05. RESULTS: No significant differences in scalloping and nerve root sleeve diameter were shown between groups. A significant difference was measured for dural sac ratios at L5 and S1 (F test, P = .003 and P < .001 at L5 and S1, respectively; post hoc t test for groups A vs C, P = .004 and P < .001 at L5 and S1, respectively). Significant differences were also obtained between groups A and C for sagittal dural sac width at S1 greater than that at L4 according to the calculated mean difference (for both F test and post hoc t test, P < .001 and P = .003 at S1 and L4, respectively). The Ahn et al and Fattori et al classifications were of limited value. CONCLUSION: The data suggest that only dural sac ratio at L5 and S1 and a sagittal dural sac width at S1 greater than that at L4 are statistically significant criteria for the assessment of dural ectasia in children, adolescents, and young adults.

Bile resistance of coated transjugular intrahepatic portosystemic shunt stents in a flow-model.

PURPOSE: We sought to test the bile resistance of transjugular intrahepatic portosystemic shunt (TIPS) stents with 3 different coatings. MATERIALS AND METHODS: Three stents with different coating materials (monolayer polyethylene terephthalate [PETP], monolayer polytetrafluoroethylene [PTFE], and double layer [PTFE]) were tested in a flow model. After testing the sealing of the system with isotonic saline solution, fresh human bile was circulated. Constant pressure was 50 cm H2O. Bile resistance of the stent membranes was analyzed. RESULTS: Two of the 3 stents proved completely resistant to water. Only the PETP stent was resistant to bile. The PTFE-coated stents were not bile resistant. CONCLUSION: The bile resistance of coated TIPS stents and, thus, the dependency of TIPS shunt patency is called into question. The stent with the reported superior patency rates does not show experimental bile resistance.

Normal brain maturation characterized with age-related T2 relaxation times: an attempt to develop a quantitative imaging measure for clinical use.

OBJECTIVES: We studied age-related changes in T2 relaxation times from the normal maturating human brain under routine clinical MR examination conditions. MATERIALS AND METHODS: In 70 healthy subjects aged between 3 weeks and 39 years, T2 maps of the brain in which the intensity of each pixel corresponded to T2 relaxation times were generated based on magnetic resonance imaging data collected with a triple spin echo sequence. T2 relaxation times in white matter (WM) and gray matter (GM) were measured in 6 distinctive regions of interest of the T2 maps. The age dependence of the T2 values was mathematically simulated using a biexponential function. RESULTS: T2 values were largest at the age of 3 weeks (maximum: approximately 400 milliseconds for WM and 200 milliseconds for GM) and decreased continuously with increasing age, faster in the first few months and slower thereafter, until values achieved between 95 and 110 milliseconds for WM and 88 and 95 milliseconds for GM in adults. The relationship between T2 values and age could be well simulated using a biexponential function (R > 0.92). CONCLUSIONS: T2 relaxation time correlates well with the progress of brain maturation. The used biexponential function reflects the dynamic development of myelination in newborns and young children as well as the maturation of myelination during adolescence and could be used to develop a "normal" reference for neuroradiological diagnoses.

Huntington disease: a case study of early onset presenting as depression.

Huntington disease is a dominantly inherited, neurodegenerative disease characterized by choreiform movement disturbances and dementia, usually with adult onset. The rare juvenile-onset Huntington disease differs from the adult phenotype. A case presenting twice, at age 10 with all the signs of a major depression and age 14 with mutism and rigidity, is reported. Meanwhile, the father developed the adult variant of Huntington disease. The boy's diagnosis was confirmed by molecular genetic analysis and magnetic resonance imaging. It is important to be aware of hereditary conditions such as Huntington disease and to provide family counseling before genetic testing and after the diagnosis is confirmed.

Predictors of apparent diffusion coefficient normalization in stroke patients.

BACKGROUND AND PURPOSE: We sought to describe the frequency of normalization of apparent diffusion coefficient (ADC) values that are decreased in hyperacute stroke and to identify characteristics of tissue demonstrating normalization. METHODS: Sixty-eight acute ischemic stroke patients underwent MRI examination (including diffusion/perfusion imaging and MR angiography) within 6 hours (mean, 2.8 hours) after symptom onset, after 24 hours, and again 4 to 7 days later. Lesion volumes with decreased ADC and delayed time to peak in perfusion imaging were determined. In patients showing ADC normalization, volumes with ADC decrease graded as <50%, 50% to 60%, 60% to 70%, and 70% to 80% of the contralateral value were determined by thresholding. Patients were categorized as normalizers (demonstrating ADC normalization in >5 mL tissue with initially decreased ADC) or nonnormalizers (demonstrating ADC normalization in <5 mL tissue). RESULTS: Fourteen patients (19.7%) were classified as normalizers. Eleven of 31 patients (35.5%) initially imaged <3 hours after stroke onset and 3 of 37 (7.5%) of those imaged 3 to 6 hours after onset were normalizers. ADC normalization occurred predominantly in the basal ganglia and white matter after thrombolytic therapy in patients with more distal vessel occlusions. All normalizers demonstrated at least partial tissue reperfusion. Tissue with more severe initial decrease in ADC was less likely to demonstrate normalization. CONCLUSIONS: ADC normalization is not a rare event in acute stroke after tissue reperfusion. Brain tissue with initially decreased ADC, especially within 3 hours after stroke onset, may include "tissue at risk."

Endovascular treatment of internal carotid artery stenosis: effect of primary stent application on debris particle release in human cadaveric specimens.

PURPOSE: To compare debris release with primary stent application (self-expanding stent application at stenosis and then balloon dilation through the opened stent) and that with secondary stent application (balloon angioplasty of stenosis and afterward additional stent application) for high-grade internal carotid artery stenosis in human cadaveric specimens. MATERIALS AND METHODS: Fresh human cadaveric internal carotid artery specimens were attached to a tube system. High-grade stenoses (>66%) were selected, randomized for primary or secondary stent application, and then treated, with fluoroscopic guidance, while the system was rinsed in a pulsating flow. Fluid was collected and filtered, and debris particles were examined with a light microscope. Particles were analyzed according to those consecutively caught by 100 x 100-microm and 11 x 11-microm mesh filters. Results were evaluated in relation to stent application. For statistical analyses of group differences, the exact Mann-Whitney U test was used. RESULTS: Thirteen high-grade human cadaveric internal carotid artery stenoses were analyzed. Five specimens were randomly assigned to secondary stent application, and eight were assigned to primary stent application. No significant difference could be demonstrated for debris release with primary or secondary stent application. P values ranged from.051 to.754. CONCLUSION: The reported superiority of primary stent application may not be related to debris reduction.

Atypical focal MRI lesions in a case of juvenile Alexander's disease.

We present a juvenile case of Alexander's disease with atypical focal magnetic resonance imaging-detected lesions and elevated levels of lactate in cerebrospinal fluid. The diagnosis was based on the neuropathological finding of a diffuse accumulation of Rosenthal fibers within the brain and the spinal cord. The diagnosis was confirmed by detection of a mutation in exon 1 at nucleotide position 249 of glial fibrillary acidic protein cDNA, a finding previously reported in cases of infantile Alexander's disease.

Cerebral blood flow predicts lesion growth in acute stroke patients.

BACKGROUND AND PURPOSE: We sought to study the role of MRI-derived cerebral blood flow (CBF) measurements for the prediction of lesion development in acute stroke patients. METHODS: Thirty-two patients were treated with tissue plasminogen activator. Diffusion-weighted (DWI) and perfusion-weighted MRI, T2-weighted imaging, and MR angiography were performed before treatment (2.8+/-0.9 hours after symptom onset) and on follow-up (days 1 and 7). CBF thresholds (12 and 22 mL/100 g per minute) were applied to bolus tracking MRI maps to determine predictive cutoff levels. RESULTS: In 21 patients (group A), the terminal lesion volume (T2-weighted imaging) was larger than the initial DWI lesion volume (89+/-93 versus 21+/-38 mL). In 11 patients (group B), the terminal lesion volume was smaller than the initial DWI lesion volume (7+/-27 versus 15+/-29 mL). The initial DWI lesion volume did not differ between both groups. The presence of a tissue volume > or =50 mL with a CBF value < or =12 mL/100 g per minute was predictive for lesion enlargement to day 7 in T2-weighted imaging (positive predictive value, 0.80). CONCLUSIONS: The presence of a tissue volume > or =50 mL with a CBF value < or =12 mL/100 g per minute predicts further lesion growth in hyperacute stroke patients. MRI-derived CBF values, with all their present limitations, are valuable in early estimation of prognosis of stroke patients.